Whatever we might think of the new Labour government’s leadership, I think this shows why we need a successful few years. Perhaps I’m being paranoid but if the country is disappointed with Labour I don’t want them to resort to electing an even more right wing version of the Tories further down the line.
We need Labour to put aside its refusal to work with other parties in the same way the French coalition did.
LibDems and Greens got more votes than Reform, and in 2015, 2017 and 2019 Labour and LibDems had a combined popular vote greater than the Tories although how that would shake out with FPTP is debatable.
People might consider LibDem to be further right than Labour, but their policies have always been pro-LGBT+, pro-green policies, pro-EU, pro-electorial reform, essentially the opposite of Reform.
[Edit] The cost of them not playing together will be far greater.